[21.02] Radio Fields Around Unidentified EGRET Sources

The second EGRET catalog and its supplement (Thompson et al.
1995, 1996) contain 157 point sources detected at energies
between 30 MeV and 20 GeV. Just about 40 % of these sources
have been identified with objects also detected at lower
energy bands, like pulsars and blazars. Of the unidentified
sources, 56 are located at galactic latitudes \mid b \mid >
10\circ, and 40 at \mid b \mid < 10\circ.

We present here the results of 1.42-GHz continuum and
HI-line observations of the environs of the unidentified
EGRET sources 2EG J0720-4746, 2EGS J0724-5157, and 2EG
J1648-5042, obtained with single dish telescopes at IAR.

From these observations we have found that the most likely
radio counterparts of 2EG J0720-4746 and 2EG J1648-5042 are
extragalactic sources, namely J0721-4744 and J1650-5044. On
the other hand, a galactic origin seems feasible for 2EGS
J0724-5157: it is supported by the detection of a nonthermal
source positionally coincident with a minimum in the HI maps
at a velocity of -3± km s-1. The possibility of a
SNR interacting with a nearby cloud, in a similar case to
that disclosed by Combi et al (1998), should be explored in
the future. References: Combi J.A., et al. 1998, A&A
333, L91; Thompson D.J., et al. 1995, ApJS 101, 259;
Thompson D.J., et al. 1996, ApJS 107, 227.

If the author provided an email address or URL for general inquiries,
it is as follows: